Wireless communications is becoming increasingly important, with wireless systems finding their way into every growing numbers of applications. Wireless systems are become ubiquitous in the military environment.
A common arrangement for a wireless network is a hub-spoke communications system. In a hub-spoke communications system, a hub terminal communications with a number of spoke terminals. For example, a hub terminal can communicate with spoke terminals within a geographic area in which the hub terminal is centrally located. Of course, such a physical arrangement is not essential, and a hub terminal need not be centrally located among the spoke terminals. Examples of hub-spoke communications systems include cellular networks (where a base station is an example of a hub terminal, and mobile terminals are examples of spoke terminals) and satellite networks (where a satellite is an example of a hub terminal, and ground terminals are examples of spoke terminals). Networks can also include multiple hub terminals.
In a hub-spoke network, communications between spoke terminals can be routed through the hub terminal (or through multiple hub terminals). For example, communications from spoke terminals can be to the hub terminal via an uplink (e.g., one or more channels), and communications from the hub terminal to spoke terminals can be on a downlink (e.g., one or more channels). Thus, for example, a message from a first spoke terminal to a second spoke terminal can be sent from the first spoke terminal to the hub terminal on the uplink, and then sent from the hub terminal to the second spoke terminal on the downlink. On one hand, this architecture can provide for increased communications capability, as spoke terminals need not be able to communicate directly (e.g., need not have line-of-sight connectivity to each other). On the other hand, the relay through the hub can reduce reliability, as interruptions in communications on either the uplink or the downlink can result in the loss of a message. Moreover, in communications systems where the hub terminal is disposed on a mobile platform, there can be an increased likelihood of blockage on either the uplink or downlink which can further reduce end-to-end message transfer reliability.